For "bricked" devices or a clean install, use Allwinner's official tools. How to Update Your Android Head Unit | Firmware/Build
Updating the firmware on an Allwinner T8 head unit involves two distinct components: the Android OS (System) MCU (Microcontroller Unit) allwinner t8 firmware update
: Copy the firmware files (usually an .img file or a zip containing update_car ) directly to the root directory of the drive. For "bricked" devices or a clean install, use
adb reboot recovery
Select “Apply update from USB.” The system will verify the package and start flashing. This takes . allwinner t8 firmware update